Pen



FIG. 1 is a front perspective view of a pen, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof; and,

FIG. 4 is side elevation view thereof, the opposite side view being a mirror image thereof.

The broken lines shown in the drawings are for illustrative purposes and form no part of the claimed design. 

I claim, the ornamental design for a pen, as shown and described. 